Equine viral respiratory infections are commonly associated with movement of horses and annually respiratory outbreaks are reported throughout the world. Equine Influenza 2 (AE2-H3N8), Equine Herpesvirus 1 and 4 (EHV1/4), and Equine Rhinitis A and B Viruses (ERAV and ERBV, respectively) are among the most important viruses isolated from the upper respiratory tract during respiratory outbreaks.
In particular, ERAV has been reported in acute febrile respiratory disease in horses (Li et al., J. Clin. Microbiol. 35:937-943; 1997, incorporated by reference). Similarly, a recent study in Ontario found ERBV and ERAV to be highly prevalent in the horse population (Diaz-Mendez et al., The Canadian Journal of Veterinary Research 74:271-278; 2010, incorporated by reference). Clinical signs of ERAV infection are non-specific and difficult to differentiate from other respiratory viral infections, including equine influenza and herpes virus infections. Non-cytopathic strains of this virus have been identified in equine respiratory outbreaks (Li et al., J. Clin. Microbiol. 35:937-943; 1997) making its diagnosis challenging. Moreover, ERAV and ERBV, being single stranded RNA viruses, have the potential for mutation, rendering the ability of the immune system to protect an animal against disease caused by a given ERAV/ERBV strain unclear.
A need exists for methods and medicaments for preventing respiratory diseases or for reducing the incidence or lessening the severity of clinical symptoms associated with such diseases, including those associated with Equine Rhinitis A and B Viruses.